Here's a patch for a \cd (change dir) command in psql program.
It's very small and only adds a few lines.
Personally, I am surprised psql does not have this command.
It is EXTREMELY useful when \include'ing SQL scripts to set
up a database schema.
Hope you like,
Mark Hamby
P.S. I am not on the 'psql-patches' list, so responses should
be sent directly to me for more info or questions.